1. Field
This disclosure relates generally to oscillator circuits, and more specifically, to a crystal oscillator circuit having fast start-up and method therefor.
2. Related Art
One type of crystal oscillator circuit, commonly known as a Pierce oscillator, is frequently used to generate clock signals in integrated circuits. This type of oscillator circuit is formed by connecting a resonator (quartz crystal) between the input and output of an inverting amplifier with one capacitor connected between ground and the input of the inverting amplifier and a second capacitor connected between ground and the output of the inverting amplifier. Usually, the inverting amplifier is formed on an integrated circuit with two pins for connecting the resonator and the two capacitors.
The crystal oscillator circuit is inherently stable so that it takes a significant amount of time and energy just to start oscillating. The rate of energy consummation is less after the circuit starts oscillating. In battery powered applications it is important for long battery life to consume as little energy as possible. Therefore, what is needed is an oscillator circuit that solves the above problems.